This invention relates to an apparatus for detecting whether or not information is recorded on a storage device such as an optical disk or a magnetooptical disk.
Conventional information recording and reproducing systems using optical disks are generally equipped with apparatuses for detecting whether or not information is already recorded in tracks on the disks. In such detecting apparatuses, an envelope is extracted from an output signal of an optical head which represents information in the disk track. The level of the envelope is used in determining whether or not information is already recorded in the disk track.